urine T cell hybridomas for ovalbumin (OVA) and insulin have een produced and tested for ability to regulate the responses f specific B cells. Several categories of T cell hybridomas ave been described. Some kinds of T cell hybridomas secrete L-2 specifically when stimulated with the correct antigen, nsulin or OVA, and, in addition, help OVA-specific istocompatible B cells or TNP-specific histocompatible B cells ake antibodies while others do not help specific B cells make ntibodies. Other T cell hybridomas are self-reactive but not ntigen specific and these augment suboptimal numbers of ntigen primed T cells in B cell secretion assays. For the nsulin system, B cell hybridomas antibodies have been used to repare anti-idiotypic reagents that do not affect IL-2 ecretion by anti-idiotypes clearly does produce regulatory ffects in an insulin immune response when examined in in vivo r in vitro assays. Future work will involve further xperiments to define cellular control of the network activated y this anti-idiotype. In other recently initiated xperiments, human-mouse T cell hybrids are being used to study ew human surface molecules at both the protein and gene levels.